The polyphenylene sulfide (hereinafter also called “PPS”) resin is an engineering plastic having excellent heat resistance, flame retardancy, chemical resistance, electrical insulation, moist heat resistance, mechanical strength and dimensional stability. The PPS resin is moldable to various molded products, fibers, films and the like by any of various molding techniques such as injection molding or extrusion molding and is practically used in a wide variety of fields including electric and electronic parts, mechanical parts and automobile parts. The PPS resin, however, has relatively low breakdown voltage and high relative permittivity as the problem. Especially in the electric and electronic fields and communication field, a material of low relative permittivity is required, accompanied with an increase in frequency for the purpose of high-speed processing and high-speed transmission of information.
A tetrafluoroethylene/hexafluoropropylene copolymer, an ethylene/tetrafluoroethylene copolymer and a tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer which are fluororesins generally have excellent non-adhesiveness, mold releasability, heat resistance, chemical resistance, slidability and electrical properties and additionally have the advantage of melt processability even in the fluororesin.
Various techniques have been proposed to mix the polyphenylene sulfide resin with the fluororesin and provide various physical properties which are not readily obtained by the simple substance (for example, Patent Document 1).